Contact person
Gerhard Scheepers
Forskare
Contact Gerhard
High-resolution wood characterisation in laboratory environment
High-resolution wood characterization is mostly done in tree breeding and genetic studies in collaboration with researchers from academic and research institutes. The samples analysed can be drill cores or cross-cut discs from well-planned field or greenhouse tests.
In our group, we use a combination of knowledge of measurement technology, wood, data analysis and modeling to describe the physical and chemical properties of wood samples. Two different devices are usually used to retrieve the information: the SilviScan system and a near-infrared (NIR) imaging instrument.
SilviScan
Silviscan measures the physical properties of the wood sample from pith to bark. The instrument consists of three measurment stations: microscopy (cell scanner), X-ray densitometer and X-ray diffractometer. From the three stations one can study cell-diameter, cell wall thickness, microfibril angle, wood stiffness and density profile. The density is measured at 25 µm resolution and is used to identify the year rings and to quantify the amount of early and latewood.
Imaging NIR
To describe the chemical composition of the wood, a line spectrometer in the NIR light wavelength range (900–2500 nm) is used to scan whole samples, in combination with chemical analyzes of parts of the scanned samples. By combining these data sources, models can be developed that make it possible to see the distribution of different substances (for example carbohydrates or lignin) in the material. Similarly, SilviScan data could be used as reference information for models so that the distribution of the physical properties, such as density and microfibril angle, could also be predicted based on NIR spectra.
The instrument can easily be adapted to image samples of different sizes, for example larger pulleys and small greenhouse samples, where a resolution of 30 µm2 can be reached for the smaller samples.
Measurement data from the laboratory are used in several types of projects. An example is the development of models for predicting wood and fiber properties in trees and logs. In other projects, the effect of the fundamental fiber properties on the pulp and sheets of paper has been studied. Data from the instruments have also been used in several concluding and ongoing plant breeding projects where the goals are, among other things, to interpret the effect of genetics on wood and fiber properties, including wood chemistry.
